Improved electrochemical performance of hierarchical porous carbon/polyaniline composites

Polyaniline (PANI)-coated hierarchical porous carbon (HPC) composites (HPC/PANI) for use as supercapacitor electrodes were prepared by in situ chemical oxidation polymerization at 273 K of an aniline solution containing well-dispersed HPC particles. After polymerization, a thin layer of PAN! was coated on the surface of the HPC particles, which was confirmed by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM) and scanning electron microscopy (SEM). Compared to pure PAN! and HPC, the electrochemical capacitance performance of the composites was significantly improved. The highest specific capacitance of the composites obtained is 478 Fg(-1) at 1 mV s(-1), which is more than twice as that of pure PANI and three times as that of pure HPC. Because of the influence from the hierarchical pore structure of the carbon material, the calculated specific capacitance of PAN! in the composite (pseudocapacitance contribution from PANI) is almost one magnitude higher than that of pure PANI. (C) 2012 Elsevier Ltd. All rights reserved.